Composition
Beryllium aluminium silicate (Be₃Al₂Si₆O₁₈) — beryl coloured by iron
Hardness · Crystal system
7.5–8 · Hexagonal
Mined in
Brazil, Nigeria, Madagascar, Pakistan, Zambia
Same mineral family as emerald. The difference is the trace element: iron makes aquamarine, chromium makes emerald.
Traditionally linked to calm communication and steadiness under pressure.
Care. Warm soapy water. Ultrasonic is usually safe, but not if the stone has visible inclusions.
Spotting a fake. Blue glass and blue topaz are the common substitutes. Aquamarine is pleochroic — tilt it and the blue shifts between blue and near-colourless. Glass does not.
Composition
Chalcedony (cryptocrystalline quartz) with inclusions of red iron oxide
Hardness · Crystal system
6.5–7 · Trigonal
Mined in
India, Brazil, Australia, Scotland
The red spots are iron oxide, not blood — but the resemblance drove nearly all of its folklore.
Traditionally carried for courage and endurance, particularly by athletes and soldiers.
Care. Warm soapy water and a soft cloth. Avoid harsh chemicals, which dull the surface.
Spotting a fake. Dyed jasper is sold as bloodstone. Genuine bloodstone has irregular, uneven red flecks; dyed material shows colour concentrated in cracks.